I'd prefer the rate to be far higher than 56.5:1 myself. So far, that isn't the case. I can't help but believe that NASA's loss rate projections were pulled out of someone's anal data store, or were more a case of wishful thinking than anything else.

As someone who studies aviation and space history, I find it interesting how some loss rates are considered acceptable, especially in wartime.

In WWI, the average operational lifetime for a pilot was less than 10 hours. Some lasted for months, some even survived the war after years of combat, but for every one of them, there were a lot of others who were shot down (and most often killed - no parachutes) on their first or second mission.

In WWII, the odds were a little better. Through much of 1942, 43, and well into 1944, the odds that a bomber crewman in the 8th Air Force would live though his 25 mission were almost zero. Sure, some did make it through, but a lot were lost very early in their combat rotation. A friend of mine survived his 25 missions in 1944 and extended for another tour. He says now that it was one of the worst decisions he ever made. He was a combat check pilot who determined when new crews were ready for combat. He and his crew were shot down on his 28th mission. For everyone else on the plane, it was their first mission.

Back then, a loss rate of 4% on a raid was considered acceptable. Anything over 4% wasn't considered sustainable. Think about that - on a big raid with 1000 bombers, a 4% loss means 40 bombers went down. Each bomber carried a crew of 9 or 10 men, so you're talking about the loss of 360 to 400 men as being considered "acceptable." On some raids, the losses were far, far higher than 4%. To put it in perspective, about 12,000 B-17 bombers were built during the war. About 4,000 of them were lost in action. Each had a crew of 9 or 10 men. That's only one kind of plane, too.

Even as late as the Vietnam war, there were some planes that suffered very high losses. One notable example was the F-105. A significant percentage of the men assigned to fly the plane didn't make it through their tour of 100 missions. The really lucky ones were rescued. The not so lucky ones spent the rest of the war as POWs. The rest were killed.

Go ahead and look at the space program. See how many close calls there were even before the Shuttle. Read about Gordon Cooper's Mercury flight where one system after another failed. Check into Armstrong's Gemini flight that almost ended in disaster. Think about Apollo 12 getting struck by lightning during liftoff, and the very close call with Apollo 13. Never for a minute forget Apollo 1, either.

There were 6 Mercury flights, 12 Gemini flights, and 15 total manned Apollo flights counting the 3 Skylab and 1 Apollo-Soyuz mission (not counting Apollo 1). That was a total of 33 manned missions before the Shuttle and quite a few close calls, near disasters, and 3 deaths on the pad. There were also deaths not immediately connected to a flight, like Bassett and See's deaths in a plane crash while visiting the Gemini factory. It's a damned dangerous business and likely will be for some time to come.